it('should stringify explicitly allowed fields', function () {
        var resumeToken = new ResumeToken(TOKEN_OBJ);

        resumeToken.set('notStringified', true);

        // the value is saved, but not stringified.
        assert.equal(resumeToken.get('notStringified'), true);

        var stringified = resumeToken.stringify();
        var parsed = ResumeToken.parse(stringified);
        for (var key in TOKEN_OBJ) {
          assert.equal(parsed[key], TOKEN_OBJ[key]);
        }
        assert.isFalse('notStringified' in parsed);
      });
 it('should populate the resume token', function () {
   var resumeToken = new ResumeToken(TOKEN_OBJ);
   for (var key in TOKEN_OBJ) {
     assert.equal(resumeToken.get(key), TOKEN_OBJ[key]);
   }
 });